Illumination apparatus

ABSTRACT

A darkfield type illumination apparatus for performing slide agglutination tests or the like. The apparatus comprises an elongated casing having an opening therein over which a transparent slide carrying the material to be illuminated is positioned. In the preferred form of the apparatus, a nonreflective surface is provided in the casing below the opening. An elongated light source is positioned below such surface. A pair of angularly bent elongated light conducting members are positioned on opposite sides of the casing with one end of the members located adjacent to the light source and the other end extending upwardly at an angle toward the opening so that rays of light transmitted through the members intersect near the opening to obliquely illuminate the material on the slide. Other configurations of the apparatus are also disclosed.

United States Patent Miller [451 Sept. 19, 1972 Inventor:

US. Cl ..240/2 MA, 240/1 EL Int. Cl ..F2lv 7/05, G02b 21/10 Field of Search ..240/2 MA, 1 EL References Cited UNITED STATES PATENTS 3/ 1934 Straubel ...240/2 MA 7/ 1946 Goldberg ..240/1 EL 7/1923 Ott ..240/2 MA 4/1935 Kraft ..240/2 MA 9/ 1933 Straubel ..240/2'MA Primary Examiner-Louis R. Prince Assistant Examiner-Denis E. Corr Attomey-Thomas L. Peterson and Robert J. Stein meyer [57] ABSTRACT A darkfield type illumination apparatus for performing slide agglutination tests or the like. The apparatus comprises an elongated casing having an opening therein over which a transparent slide carrying the material to be illuminated is positioned. 1n the preferred form of the apparatus, a nonreflective surface is provided in the casing below the opening. An elongated light source is positioned below such surface. A pair of angularly bent elongated light conducting members are positioned on opposite sides of the casing with one end of the members located adjacent to the light source and the other end extending upwardly at an angle toward the opening so that rays of light transmitted through the members intersect near the opening to obliquely illuminate the material on the slide. Other configurations of the apparatus are also disclosed.

4 Claims, 5 Drawing figures P A T TED I97? 3.692.997

INVENTOR BY 1 n 1 ATTORNEY ILLUMINATION APPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to an illumination apparatus and, more particularly, to an apparatus for illuminating a material on a transparent slide such as is used in slide agglutination tests.

2. Description of the Prior Art Slide agglutination tests are employed in medical laboratories for the purpose of ascertaining the type of a persons blood. This is important in cases of blood transfusion where care is to be taken that the blood of the donor be of the type compatible with the blood of the patient who is to receive said blood as otherwise the transfusion might result in an unfavorable reaction or even death of the patient.

At the present time, such agglutination tests are being performed by placing slides carrying the bloodblood typing serum mixture upon a frosted glass of a box-like viewer from which light is directed through the frosted glass against the slide and the contents thereof. The test is also sometimes performed by holding the slide over a regular incandescent light in such a manner that some of the rays of the light pass obliquely through the bottom of the slide. Still another method uses an opague slide, such as a plastic coated cardboard, which is illuminated from above by a regular incandescent light. All these methods suffer from the fact that the type of lighting does not provide good contrast between the agglutinated particles on the slide and the background material thereby making reading of weak agglutinations difficult.

SUMMARY OF THE INVENTION The principal object of the present invention is to provide an improved illumination apparatus for performing slide agglutination tests'or the like.

Another object of the invention is to provide a darkfield type apparatus for illuminating agglutination reactions which allows the reactions to be easily read with the naked eye.

According to the principal aspect of the present invention, there is provided a darkfield type illumination apparatus for performing slide agglutination tests or the like. The apparatus comprises an elongated casing having an opening therein over which a transparent slide carrying the material to be illuminated is positioned. A nonrefletive surface is provided in the casing below the opening. An elongated light source is positioned below such surface. A pair of angularly bent elongated light conducting members are positioned on opposite sides of the casing with one end of the members located adjacent to the light source and the other end extending upwardly at an angle so that rays of light transmitted through the members intersect near the opening to obliquely illuminate the material on the slide.

In another embodiment of the invention, a reflective surface is formed on each of the angularly bent light conducting members and is positioned to reflect light from the source to the opening in the casing. In still a further embodiment, two light sources are provided which are positioned adjacent to the edges of two flat angularly disposed light conducting members. In each embodiment, the apparatus is characterized by simplicity in construction yet produces a darkfield type illumination over an elongated opening so that a plurality of agglutination reactions or the like can be viewed more accurately and easily than heretofore.

' BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a preferred form of the apparatus of the present invention with a blood typing slide mounted thereon;

FIG. 2 is a somewhat enlarged transverse vertical sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a vertical longitudinal sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is a transverse sectional view similar to FIG. 2 showing a modified from of the apparatus; and

FIG. 5 is a transverse sectional view through a further embodiment of the apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawing in detail, wherein like reference characters designate like or corresponding parts throughout the various views, there is shown in FIGS. 1-3 the preferred embodiment of the apparatus of the present invention. In FIG. 1, an agglutination slide 10 is shown as supported on top of the illumination apparatus of the invention, generally designated 12. The slide 10 is formed of a transparent material, preferably plastic, and is shaped to provide a plurality of circular depressed wells 14, four being shown by way of example only. The apparatus 12 is designed to provide a darkfield type of illumination so that agglutination reactions occurring in the wells may be accurately and easily seen by the naked eye.

More specifically, the apparatus 12 includes an elongated casing 16 preferably in the form of a metal or plastic sheet which is bent to form a bottom 18 and a pair of sides 20 joined by curved comers 22. The sides 20 extend toward each other at an acute angle with respect to the bottom 18. The longitudinally extending ends 24 of the sides 20 are spaced apart to provide an elongated longitudinally extending opening 26. The casing 16 is closed at its opposite ends by plates 27.

The outer edges 28 of the slide 10 are turned downwardly to engage the upper surface of the sides 20 of the casing 16 when the slide 10 is positioned over the opening 26. The wells 14 in the slide 10 are located along the center line of the slide and thus are positioned in the middle of the elongated opening 26.

A generally flat elongated support plate 30 is positioned on the bottom 18 of casing 16. An arcuate longitudinally extending channel 32 is formed in the upper surface of the support plate 30. This channel is positioned below the center line of the elongated opening 26. Preferably, a single elongated tubular incandescent or fluorescent lamp 34 is positioned in the channel 32. As best seen in FIG. 3, the lamp is provided with an elongated filament 36 which extends substantially the length of the casing 16 to thereby provide a continuous, elongated source of illumination for the apparatus. Alternatively, the elongated source of illumination could be intermittent by providing a series of short filament lamps (not shown) positioned in the channel 32, one below each well 14 in the slide. A conductor 38 extends from one end of the light 34 through end plate 27 and terminates in a plug 40 which is adapted to be connected into a conventional household electrical outlet for supplying electrical current to the light to energize the same.

A pair of elongated members 42 are positioned longitudinally within the casing 16 adjacent to the opposite sides 20. These members are formed of transparent light conducting material such as Lucite or transparent vitreous silica. Each member is bent to an acute angle along it longitudinal extent to provide a base 44 and an upper plate 46 joined by a curved connecting section 48. The angularly bent members 42 are positioned within the casing so as to open toward each other. The bases 44 are supported by the plate 30 and their longitudinally extending end surfaces 50 are positioned adjacent to the light source 34. The upper plates 44 of the members 42 extend upwardly at an angle such that their transverse planes, indicated by dotted lines 52, intersect each other within the opening 26 and preferably at the bottom of the well 14.

A generally flat elongated element 54 lies on top of the bases 44 of members 42 and extends the length of the casing 16. The outer edges 56 of element 54 are tapered and extend into the hollow angular channels provided between the respective bases 44 and plates 46 or members 42. An arcuate longitudinally extending channel 58 is formed in the bottom of element 54 above the channel 32 in support plate 30 whereby the two channels provide a generally cylindrical cavity for the light source 34.

The element 54 performs two functions. Flrst, it serves as a spacer between the members 42 to assure that the end surfaces 50 will be spaced slightly from the cylindrical surfaces of the source 34. In addition, the element 54 provides a nonreflective surface 60 disposed in the direction of the opening 26. This nonreflective surface may be provided by forming the element from an opaque, preferably black, plastic. Altern'atively, the element could be formed of a transparent or reflective material but coated on its outer surface with a suitable nonreflective layer.

Preferably the ends 24 of sides of the casing overhang the ends 62 of the light conducting plates 46 to a sufficient distance such that an observer looking down into the opening 26 cannot see the ends 62. The bottom of the overhanging portions of the sides 20 are provided with a nonreflective coating. Thus, there will be provided a nonreflective background below the slide It can be appreciated that when the light source 34 is energized, an elongated beam of light will be transmitted by the angularly bent members 42 so that light rays will be directed along the planes 52 to obliquely illuminate particles in the wells, 14 of the slide 10. It has been found that the oblique illumination with the black background provided by the apparatus 12 of the present invention produces an effective darkfield type illumination so that agglutination reactions may be easily read by the naked eye.

Referring now to FIG. 4 of the drawing, there is illustrated another embodiment of the apparatus which is almost identical to the apparatus 12 except that the connecting sections 48 of the light conducting members 42 are machined along their outer edges as indicated at 70 to provide a flat surface which is essentially perpendicular to the plane 52. The surface 70 is coated with a suitable reflecting material, such as aluminum paint, so that light rays emanating from the elongated light source 34 will be transmitted by the base 44 to the reflecting surface 70, and reflected therefrom along the plane 52 to the bottom of the well 14 in the slide 10. It is noted that in the embodiment disclosed in FIG. 4, the end surfaces 50 of the bases 44 of members 42 have a convex configuration to thereby act as a condenser for providing nearly parallel light rays from the source 34 to the reflecting surface 70. However, the surfaces 50 could be flat as shown in FIG. 2, but with some sacrifice in the intensity of the light that is transmitted to the slide 10. Likewise, the surfaces 50 on the members 42 in FIG. 2 could be convex, if desired.

Referring now to FIG. 5, a further form of the invention is disclosed wherein two elongated light sources 34 are provided along the opposite edges 22 of the casing 16. Flat light conducting plates 46 are positioned between the sources 34 and the opening 26 within the casing over which the slide 10 is mounted. As in the other embodiments of the invention, the plates 46 are disposed at an angle so that their transverse planes 52 will intersect at the bottom of the wells 14 in the slide 10.

It can be appreciated that by the present invention there is provided a simple and inexpensive apparatus for illuminating materials on transparent slides. By the use of an elongated light source and elongated light conducting materials, various substances may be viewed in a plurality of wells in an elongated transparent slide with the light rays from the source obliq uely illuminating the substances which are easily visible to the naked eye due to the black background provided underneath the slide. Furthermore, while the invention has been described particularly in connection with the performance of slide agglutination tests, obviously the apparatus may be employed for illuminating other objects, such as immunoelectrophoresis plates, for examination.

Although several embodiments of the invention have been disclosed herein for purposes of illustration, it will be understood that various changes can be made in the form, details, arrangement and proportions of the various parts in such embodiments without departing from the spirit and scope of the invention as defined by the appended claims.

What is claimed is:

1. An apparatus for illuminating a material on a transparent slide comprising:

an elongated casing having an opening therein extending longitudinally of the casing, said casing being adapted to support said slide over said openmg;

means providing an elongated source of illumination extending longitudinally within said casing remote from and below said opening;

means in said casing between said opening and said source providing a nonreflective surface disposed in the direction of said opening;

a pair of elongated transparent light conducting plates extending longitudinally within said casing on opposite sides of said opening, said plates extending upwardly at an angle toward said opening such that the planes in which said plates lie intersect near said opening;

means for transmitting illumination from said source to said plates in the direction of said planes so that illumination transmitted by said plates will intersect near said opening to illuminate material on said slide when positioned on said casing over said opening, said illumination transmitting means including an integral, base on each of the plates extending below said nonreflective surface adjacent said source, and the longitudinally extending end surface of the base of each of said plates adjacent to said source being of convex configuration.

2. An apparatus as set forth in claim 1 wherein:

said illumination transmitting means includes a reflective surface on each of said plates extending the length thereof and arranged to reflect illumination from said source toward said opening.

3. An apparatus as set forth in claim 1 wherein:

the base of each plate is joined to the remainder of the plate by a longitudinally extending curved connecting section capable of bending light rays from said source of illumination toward said opening.

4. An apparatus for illuminating a material on a transparent slide comprising:

an elongated casing having an opening therein extending longitudinally of the casing, said casing being adapted to support said slide over said opening;

means providing an elongated source of illumination extending longitudinally within said casing remote from and below said opening;

a pair of elongated transparent light conducting members extending longitudinally within said casing along opposite sides thereof;

each said member being bent to an angle along its longitudinal extent to provide a base and an upper plate joined by a curved connecting section, said angularly bent members opening toward each other;

the longitudinally extending end surface of each base being positioned adjacent to said source;

an elongated spacer element extending longitudinally within said casing above said source with its edges extending into the hollow angular channels formed by said angularly bent members, the upper surface of said element lying below said opening and being non-reflective; and

the planes in which said upper plates lie intersecting near said opening whereby light rays from said source of illumination will be bent by said members and will intersect near said opening to illuminate material on said slide when positioned on said casing over said opening. 

1. An apparatus for illuminating a material on a transparent slide comprising: an elongated casing having an opening therein extending longitudinally of the casing, said casing being adapted to support said slide over said opening; means providing an elongated source of illumination extending longitudinally within said casing remote from and below said opening; means in said casing between said opening and said source providing a nonreflective surface disposed in the direction of said opening; a pair of elongated transparent light conducting plates extending longitudinally within said casing on opposite sides of said opening, said plates extending upwardly at an angle toward said opening such that the planes in which said plates lie intersect near said opening; means for transmitting illumination from said source to said plates in the direction of said planes so that illumination transmitted by said plates will intersect near said opening to illuminate material on said slide when positioned on said casing over said opening, said illumination transmitting means including an integral, base on each of the plates extending below said nonreflective surface adjacent said source, and the longitudinally extending end surface of the base of each of said plates adjacent to said source being of convex configuration.
 2. An apparatus as set forth in claim 1 wherein: said illumination transmitting means includes a reflective surface on each of said plates extending the length thereof and arranged to reflect illumination from said source toward said opening.
 3. An apparatus as set forth in claim 1 wherein: the base of each plate is joined to the remainder of the plate by a longitudinally extending curved connecting section capable of bending light rays from said source of illumination toward said opening.
 4. An apparatus for illuminating a material on a transparent slide comprising: an elongated casing having an opening therein extending longitudinally of the casing, said casing being adapted to support said slide over said opening; means providing an elongated source of illumination extending longitudinally within said casing remote from and below said opening; a pair of elongated transparent light conducting members extending longitudinally within said casing along opposite sides thereof; each said memBer being bent to an angle along its longitudinal extent to provide a base and an upper plate joined by a curved connecting section, said angularly bent members opening toward each other; the longitudinally extending end surface of each base being positioned adjacent to said source; an elongated spacer element extending longitudinally within said casing above said source with its edges extending into the hollow angular channels formed by said angularly bent members, the upper surface of said element lying below said opening and being non-reflective; and the planes in which said upper plates lie intersecting near said opening whereby light rays from said source of illumination will be bent by said members and will intersect near said opening to illuminate material on said slide when positioned on said casing over said opening. 